Green Environmental Protection Research Articles

High-Performance Pomegranate-Like CuF2 Cathode Derived from Spent Lithium-Ion Batteries.

With the large-scale application of lithium-ion batteries (LIBs), a huge amount of spent LIBs will be generated each year and how to realize their recycling and reuse in a clean and effective way poses a challenge to the society. In this work, using the electrolyte of spent LIBs as solvent, we in-situ fluorinate the conductive three-dimensional porous copper foam by a facile solvent-thermal method and then coating it with a cross-linked sodium alginate (SA) layer. Benefiting from the solid-electrolyte interphase (SEI) that accommodating the volume change of internal CuF2 core and SA layer that inhibiting the dissolution of CuF2, the synthesized CuF2@void@SEI@SA cathode with a pomegranate-like structure (yolk-shell) exhibits a large reversible capacity of ~535 mAh g-1 at 0.05 A g-1 and superb cycling stability. This work conforms to the development concept of green environmental protection and comprehensively realizes the unity of environmental, social and economic benefits.

Active Methods for the Equalization of a Serially Connected Lithium-Ion Battery Pack: A Review

Traditional fuel vehicles are currently still the main means of transportation when people travel. It brings convenience to their travels, but it also causes energy shortages and environmental pollution. With the development of science and technology and the popularization of green environmental protection, electric vehicles have gradually entered people’s lives, greatly alleviating these problems. As a power supply device for electric vehicles, the performance of batteries directly affects various indicators of vehicles. Due to their long lifespan and high energy density, lithium-ion batteries are now the preferred source of power for electric vehicles. However, due to various factors in the manufacturing and operation of lithium-ion batteries, there are often differences among individual cells. The power balance and performance of a battery pack are closely related. Thus, battery equalization is an important standard for a battery management system to work normally, and it is also one of the various battery management application problems. This paper reviews battery equalization systems and various active equalization circuits and summarizes the working principle and research progress of each active equalization circuit. Then, various active equalization circuits are analyzed and compared, and dynamic equalization for a second-life battery is introduced to enrich this review of equalization technology. Finally, the above contents are summarized and prospected. In order to obtain the best outcomes, different equalization circuits need to be chosen for various situations.

Nitrogen-doped biochar derived from corn straw for CO2 adsorption: a new vision on nitrogen sources comparison

Biochar as a highly promising CO2 adsorbent is of great significance in addressing global warming and promoting human health. Research has shown that nitrogen doping improves the CO2 adsorption performance of biochar, but selecting chemical nitrogen sources such as urea and melamine to prepare nitrogen-doped biochar is not conducive to green production and environmental protection. Therefore, it is necessary to identify a new nitrogen source to enhance the emission reduction characteristics of this process. This study selected corn straw as the raw material and cow manure as a representative protein-based nitrogen source to explore its potential as a urea substitute and reveal the hydrothermal carbonization doping mechanism of different nitrogen sources. The results indicated that in raw materials with the same C/N ratio, biochar prepared from cow manure as the nitrogen source had a better doping effect and CO2 adsorption performance. Moreover, a moderate amount of cow manure was beneficial for efficient nitrogen doping and the adsorption of CO2 by biochar, with a maximum CO2 adsorption performance improvement of 32.7%. Due to the different carbon-nitrogen bonds of the different nitrogen sources, urea was more likely to retain amino groups, while macromolecular protein nitrogen sources tended to retain structural nitrogen. The results of this study provide new ideas and theoretical support for preparing other nitrogen-doped carbon materials derived from biomass.Graphical

Environmental Dyeing and Functionalization of Silk Fabrics with Natural Dye Extracted from Lac.

Most traditional synthetic dyes and functional reagents used in silk fabrics are not biodegradable and lack green environmental protection. Natural dyes have attracted more and more attention because of their coloring, functionalization effects, and environmental benefits. In this study, natural dyes were extracted from lac and used for coloring and functionalization in silk fabrics without any other harmful dyes. The extraction conditions were studied and analyzed by the univariate method. The optimal extraction process was that the volume ratio of ethanol to water was 60:40 with a solid-liquid ratio of 1:10, and reacting under the neutrality condition for 1 h at 70 °C. Silk fabric can be dyed dark owing to the certain lifting property of lac. After being dyed by Al3+ post-medium, the levels of the washing fastness, light fastness, and friction fastness of silk fabric are all above four with excellent fastness. The results show that the dyed silk fabrics have good UV protection, antioxidation, and antibacterial properties. The UV protection coefficient UPF is 42.68, the antioxidant property is 98.57%, and the antibacterial property can reach more than 80%. Therefore, the dyeing and functionalization of silk fabrics by utilizing naturally lac dyes show broad prospects in terms of the application of green sustainable dyeing and functionalization.

Flame-retardant vegetable oil-based rigid polyurethane foam constructed with Mxene@HNT and hydrogel via layer-by-layer coating

Rigid polyurethane foam (RPUF) meets the demand for green environmental protection by utilizing vegetable oil as polyol. However, enhancing its flame retardancy is essential to address safety concerns for its widespread application across various commercial sectors. In this work, we successfully prepared Mxene@HNT, and then employed a layer-by-layer coating to immobilize Mxene@HNT onto RPUF surfaces using dual hydrogel (DH), thus creating the RPUF/M@H/DH flame retardant system. Comparative analysis against standard RPUF demonstrates significant enhancements in flame retardancy, achieving a ``V-0'' rating in the UL-94 vertical combustion test, with a limiting oxygen index (LOI) of 30.5 %. Notably, in cone calorimetry test (CCT), peak heat release rates (pHRR) and peak smoke production rates (pSPR) were reduced by 29.34 % and 14.95 % respectively for RPUF/M@H-3/DH, while experiencing a 151.5 % increase in carbonization yield (CY) compared to standard RPUF. Importantly, the mechanical properties of RPUF maintained well upon surface modification to obtain flame retardant RPUF/M@H/DH. Thus, this study offers a novel perspective on addressing both environmental concerns and flame retardancy requirements for RPUF.

Engineering non-conventional yeast Rhodotorula toruloides for ergothioneine production

BackgroundErgothioneine (EGT) is a distinctive sulfur-containing histidine derivative, which has been recognized as a high-value antioxidant and cytoprotectant, and has a wide range of applications in food, medical, and cosmetic fields. Currently, microbial fermentation is a promising method to produce EGT as its advantages of green environmental protection, mild fermentation condition, and low production cost. However, due to the low-efficiency biosynthetic process in numerous cell factories, it is still a challenge to realize the industrial biopreparation of EGT. The non-conventional yeast Rhodotorula toruloides is considered as a potential candidate for EGT production, thanks to its safety for animals and natural ability to synthesize EGT. Nevertheless, its synthesis efficiency of EGT deserves further improvement.ResultsIn this study, out of five target wild-type R. toruloides strains, R. toruloides 2.1389 (RT1389) was found to accumulate the highest EGT production, which could reach 79.0 mg/L at the shake flask level on the 7th day. To achieve iterative genome editing in strain RT1389, CRISPR-assisted Cre recombination (CACR) method was established. Based on it, an EGT-overproducing strain RT1389-2 was constructed by integrating an additional copy of EGT biosynthetic core genes RtEGT1 and RtEGT2 into the genome, the EGT titer of which was 1.5-fold increase over RT1389. As the supply of S-adenosylmethionine was identified as a key factor determining EGT production in strain RT1389, subsequently, a series of gene modifications including S-adenosylmethionine rebalancing were integrated into the strain RT1389-2, and the resulting mutants were rapidly screened according to their EGT production titers with a high-throughput screening method based on ergothionase. As a result, an engineered strain named as RT1389-3 was selected with a production titer of 267.4 mg/L EGT after 168 h in a 50 mL modified fermentation medium.ConclusionsThis study characterized the EGT production capacity of these engineered strains, and demonstrated that CACR and high-throughput screening method allowed rapid engineering of R. toruloides mutants with improved EGT production. Furthermore, this study provided an engineered RT1389-3 strain with remarkable EGT production performance, which had potential industrial application prospects.

Research on the Relationship between GSCM and Enterprise Performance: a Multidimensional Analysis based on Manufacturing Industry

Green supply chain management (GSCM) refers to focusing on green environmental protection and reducing the pollution of the whole industrial chain in the process of enterprise production and cooperation with upstream and downstream, which helps to realize the coordinated development of the economy and the environment. With the increasing global environmental problems, GSCM has become an inevitable trend for the transformation and upgrading of manufacturing enterprises in China. However, the relationship between GSCM and enterprise performance has not yet reached a consensus. This paper adopted a multi-case study research method to analyze the GSCM performance of manufacturing enterprises from multiple dimensions. The results showed that GSCM enhances enterprise performance by improving economic, environmental and social performance. These performance improvements not only contribute to the long-term development of the enterprise, but also enhance the competitiveness of the enterprise and the sustainability of its development. This study would improve and enrich the theory of GSCM, and enhance the theoretical basis for enterprises to improve their competitiveness and realize sustainable development. At the same time, the study can provide reference for the government and relevant organizations to formulate and implement relevant policies, and provide important theoretical guidance and decision-making reference for realizing the high-quality development of China's economy.

Technical transformation of heavy/ultra-heavy oil production in China driven by low carbon goals: A review

With the growing global energy demand and limited production of conventional crude oil, the extraction of unconventional heavy and extra-heavy oil is receiving unprecedented attention. China is the fourth largest producer of heavy oil. High viscosity and complex formation environments increase the difficulty of exploiting heavy oil. To alleviate the economic cost and environmental pollution pressure brought by heavy oil production, China has achieved significant advancement in the innovation of heavy oil recovery, including accelerating the transformation of thermal technology to non-thermal technology and the use of new energy technology to achieve the goal of low-carbon economy and green environmental protection. Based on the background of heavy oil in China, this paper recharacterizes the high-viscosity mechanism of heavy oil. From different aspects, including basic principles, main characteristics, applicability, limitations, and challenges, this paper comprehensively reviews existing heavy oil recovery technologies, including thermal recovery, in-situ upgrading, cold recovery, and new energy technologies.Currently, in China, the main target of heavy oil recovery is achieving the “carbon peaking and carbon neutrality” goals, which can be described as low energy consumption, low emission, and low pollution. To facilitate the low-carbon transition in the extraction of heavy/extra-heavy oil and attain environmental sustainability goals, it is essential to increase the proportion of non-thermal factors in thermal recovery technologies, develop efficient in-situ catalysts, adopt clean cold extraction techniques, and advance the development of new energy technologies.

Fuzzy Evaluation Model for Products with Multifunctional Quality Characteristics: Case Study on Eco-Friendly Yarn

Numerous advanced industrial countries emphasize green environmental protection alongside athletic healthcare. Many world-renowned sports brands are actively developing highly functional, environmentally friendly, and aesthetically pleasing products. For example, in the production of sports shoes, the eco-friendly yarn process is one of the important processes. This process involves multiple crucial larger-the-better quality characteristics closely tied to the functionality of sports shoes. Facing green environmental regulations and external competitors, it is evidently an imperative issue for enterprises to consider how to improve the quality of newly developed products, increase product value, and lower rates of both rework and scrap to accomplish the goals of saving energy and minimizing waste. Aiming to solve this problem, this study proposed a fuzzy evaluation model for products with multifunctional quality characteristics to assist the sporting goods manufacturing industry in evaluating whether all functional quality characteristics of its products meet the required quality level. This study first utilized the larger-the-better Six Sigma quality index concerning environmental protection for evaluation and then proposed product evaluation indicators for the eco-friendly yarn. Since the parameters of these indicators have not yet been determined, sample data need to be used for estimation. Enterprises require rapid response, so that the sample size is relatively small. Sampling error will increase the risk of misjudgment. Therefore, taking suggestions from previous studies, this study constructed the fuzzy evaluation model based on confidence intervals of quality indicators for the eco-friendly yarn. This method incorporated previous experience with data, thereby enhancing assessment accuracy.

Can low-carbon cities pilot policy promote enterprise sustainable development? Quasi-experimental evidence from China.

With the predicament of sustainable improvement in traditional cities, the low-carbon city pilot policy (LCCPP), as a novel development mode, provides thinking for resolving the tensions of green development, resource conservation and environmental protection among firms. Using Chinese A-share listed companies panel data during 2007-2019, this study adopts the difference-in-differences model to explore the impact of LCCPP on firm green innovation. Based on theoretical analysis, LCCPP-driven environmental rules have the impact of encouraging business green innovation. The relationship between LCCPP and green innovation is strengthened by external media attention and organizational redundancy resources. The mechanism study shows that the incentive effect of LCCPP on firm green innovation is mainly due to the improvement of enterprises' green total factor productivity and financial stability. In addition, the heterogeneity analysis shows that the LCCPP has significantly positive effects in promoting green innovation in high-carbon industries and state-owned enterprises. This research contributes to the understanding of city-level low-carbon policies as a driving force for corporate green innovation, offering practical implications for policymakers and businesses striving for sustainability.

Highly effective MFe2O4 (M=Zn, Mg, Cu and Mn) spinel catalysts for Fischer-Tropsch synthesis

A series of spinel catalysts, including ZnFe2O4, MgFe2O4, CuFe2O4, and MnFe2O4, were prepared and applied to the Fischer-Tropsch synthesis (FTS). Zn, Mg, Cu and Mn easily form spinels with Fe. Among them, Zn and Mg can significantly maintain the spinel structure during the pretreatment and reaction, resulting in a low CO conversion. Cu and Mn are beneficial to the formation of iron carbide during the reaction, resulting in an apparent influence on FTS performance. ZnFe2O4 has little effect on the hydrocarbon distribution and the olefin/paraffin (O/P) ratio of C2–C4. MgFe2O4 exhibits low selectivity for C5+ hydrocarbons, and the selectivity of C= 2−C= 4 and the O/P ratio of C2–C4 in the product are increased due to the alkaline effect of Mg. Cu can promote the carbonization of the catalyst, so that CuFe2O4 has higher activity. Meanwhile, CuFe2O4 can significantly improve the selectivity of C5+ hydrocarbons. Moreover, Cu can promote the dissociation and activation of H2, which is beneficial to the secondary hydrogenation of olefins, thereby reducing the selectivity of C= 2−C= 4 and the O/P ratio of C2–C4. Mn promotes carbonization during the reaction, but MnFe2O4 has little effect on the chain growth of hydrocarbon. However, Mn can promote the generation of a certain amount of ɛ-Fe2C, which may explain the higher selectivity of C= 2−C= 4 and the O/P ratio of C2–C4 for MnFe2O4. All spinel catalysts exhibit low CO2 selectivity, which meets the current green environmental protection requirements.

Development Status and Future Prospects of Photovoltaic Cells

With the rapid development of social economy, the consumption of conventional energy is growing at an amazing rate. The energy shortage crisis and the environmental problems brought by conventional energy will seriously restrict social development and affect the daily lives of residents. Therefore, paying attention to the creation and use of new energy, protecting the environment, improving efficiency, controlling the emission of pollutants and realizing sustainable development have become the main research topics in the new era of the energy sector. Photovoltaic energy has the advantages of economic energy saving, green environmental protection, wide application and sustainability, and is an ideal new energy, that has been developed to the third generation. This paper mainly combs the development process of photovoltaic technology, summarizes the characteristics, advantages and disadvantages of the third generation of photovoltaic technology, analyzes the current situation and prospects of photovoltaic technology development, and analyzes the problems and challenges faced. This research finds that as the economy and technology continue to advance, photovoltaic cell technology is developing rapidly, and the application cost is constantly reduced. The photovoltaic cell industry will get more attention and better development, and its application prospect is very broad. The research of this topic is helpful in enhancing the comprehensive and objective understanding of the development of photovoltaic cell technology, and will provide a valuable reference in order to advance the photovoltaic sector in the future, which has important practical significance.

Study on Properties of Micro-Nano Magnetic Composite Prepared by Mechanochemical Method of NdFeB Secondary Waste and Removal of As (V) from Mine Water

The secondary waste produced by NdFeB waste after rare earth recycling, with an annual output of more than tens of thousands of tons, is the largest solid waste emission source in the rare earth industry, and long-term storage causes land resource occupation and environmental pollution. Arsenic-containing mine wastewater has serious harm, wide distribution, and long duration of pollution. In this study, the mechanical ball milling method was used to activate NdFeB secondary waste to prepare micro-nano magnetic composite materials, the main components of which are Fe2O3, Fe3O4, and C. Under mechanical mechanochemical action, the particles are more dispersed, the particle size decreases, the specific surface area increases significantly, the crystal structure changes to amorphous structure, the degree of amorphous shape increases, and the content of Fe-OH increases. Applied to the treatment of As (V) in simulated mine water, it was found that the removal of As (V) by this material was mainly based on chemisorption and monolayer adsorption, and the maximum adsorption amount reached 10.477 mg/g. Zeta, FT-IT, and XPS characterization confirmed that the removal of As (V) was a coordination exchange reaction between the material and As (V) to form an inner sphere complex. The removal rate of As (V) decreased from 94.33% to 73.56% when the initial concentration of solution was 10 mg/L, pH value was 3.0, and material dosage was 1 g/L after 5 times of regrowth. This study provides a new way for the application of NdFeB secondary waste, which has low cost, green environmental protection, and wide application prospects.

Preparation and microstructure of Cu-Al2O3 composites by a novel supercritical water liquid phase in-situ reaction method

The high solubility, reactivity and solubility of supercritical water provide a new way for the preparation of advanced metal matrix composites. In this paper, Cu-Al2O3 composites are prepared by supercritical water liquid phase in situ reaction (SW-LIR). In this method, the Cu-Al atomized alloy powder are used as raw material, deionized water as reaction medium, H2O2 as liquid phase oxygen source, and the Cu-Al2O3 composite powder are prepared at 380 ℃ and 22.1 MPa for 10 min. The Cu-Al2O3 composite block is prepared by spark plasma sintering (SPS). The results show that Al2O3 has an average size of 41.8 nm and mainly exists in the form of mixed crystals. The interface with the matrix is coherent or semi-coherent. With the increase of Al2O3 content, the mechanical properties of the composites are obviously improved. When the Al2O3 content is 1.12 wt%, the microhardness is as high as 164.52 HV and the tensile strength is 441 MPA, while still maintaining a high electrical conductivity (75 %IACS). At the same time, it shows quite excellent high temperature performance. It can still retain the characteristics of high strength at 1000℃, which solves the shortcomings of high thermal conductivity but low strength of pure copper. Compared with the traditional method, SW-LIR method has the characteristics of low reaction temperature, fast reaction speed and green environmental protection.

Research Progress of Nickel Iron Bimetallic Series Electrocatalytic Materials

Hydrogen energy has become one of the recognized clean energy sources worldwide due to its advantages such as low cost, renewable energy, and green environmental protection. Electrolytic water is currently one of the most promising solutions for providing hydrogen fuel. Nickel iron bimetallic electrocatalysts have abundant sources, low cost, clean and pollution-free properties, and strong catalytic performance, This article mainly reviews the development and research of bimetallic nickel iron oxides and nickel iron alloys in recent years, and explores their synthesis methods, properties, and stability in depth.

Analysis of wettability and oil-water separation mechanism of superhydrophilic/underwater superoleophobic mesh based on capillary force model

The Frequent oil spills at sea and large discharges of oily wastewater spills seriously jeopardize the ecological environment and lead to an increasing shortage of water resources, so the oil/water separation has become a hot spot of global research. As opposed to the conventional separation method, the membrane separation has received wide attention because of its advantages of green environmental protection, low energy consumption and easy operation. In this paper, Cu(OH)2 mesh with superhydrophilic and underwater superoleophobic properties were prepared by in-situ growth method using purple copper mesh as the substrate. Scanning electron microscopy, x-ray photoelectron spectroscopy and contact angle tests were used to evaluate the surface morphology, chemical composition and wetting behavior of the mesh. The results showed that the water contact angle was 0° in air and the contact angle was 155.4° for oil droplets underwater. The membrane exhibited high separation efficiencies (99%) and separation fluxes (3.67-6.54×104 L·m-2·h-1) for the five tested oils under gravity drive. The wettability of the mesh was unaffected after 20 separation experiments. The surface wettability and the oil/water separation mechanism were analyzed using the capillary force-based separation model combined with the Young and Cassie-Baxter equations.

Polycarboxylate superplasticizer modified 3D graphene as long-term-efficient water-based lubricating additive under heavy load conditions

At present, due to the excellent properties of graphene, which can significantly enhance the performance of lubricants, researchers are conducting extensive studies on it. However, the poor dispersion of graphene limits its application in lubrication, which becomes an urgent problem for researchers to solve. Moreover, with the concept of green environmental protection becoming more and more popular, the research on water-based lubricants is of great significance. Therefore, we modify three-dimensional graphene (3DG) by polycarboxylate superplasticizer (PCE) to prepare a water-based lubrication nano-additive with long-term dispersion stability, named PCEG. PCEG nanomaterials can stably disperse in water for more than three months, which effectively solves this problem. Tests show that friction coefficient and wear volume of the lubricant with 0.5 wt% PCEG are reduced by 31.1 % and 23.1 %, respectively, compared to the base fluid at 20 N (2.7 GPa) heavy load conditions. The enhanced lubrication performance is attributed to the fact that PCEG, which has excellent dispersion stability, forms a strong adsorption and continuous dense lubrication film on the friction surface. In addition, it fills and polishes the grooves and pits, thus improving the friction-reduction and anti-wear properties. This study not only greatly solves the problem of poor dispersion stability of graphene and develops a nano-lubricant that is consistently effective under heavy load conditions, but also provides an important reference value for the subsequent development of high-performance and stable graphene-based lubricants.

Does Investor Sentiment Drive Corporate Green Innovation: Evidence from China

Green innovation plays an increasingly significant role in sustainable development. We use the data of Chinese listed firms from 2010 to 2019 to investigate the impact of investor sentiment on corporate green innovation. The result indicates that optimistic investor sentiment significantly promotes corporate green innovation. Mechanism analysis shows that the higher the financial constraints, institutional ownership ratio, and analyst coverage of a firm, the stronger the impact of investor sentiment on green innovation, indicating that optimistic investor sentiment promotes green innovation through external financing and managerial catering channels. In addition, the impact of investor sentiment on corporate green innovation is more pronounced for state-owned firms. The study sheds light on a novel determinant of corporate green innovation and offers policy recommendations to advance green innovation, environmental protection, and sustainable development.

Human Resource Green Practices Towards Sustainability: The Case of Foxconn Company in China

This paper mainly studies whether Foxconn's green human resource management can bring benefits to Foxconn and puts forward suggestions on the problems existing in the implementation of green human resource management in Foxconn. The data for this chapter comes from Foxconn employees in Yantai, Shandong Province. Foxconn's HR green practices include green recruitment, green training, green performance, green compensation and green participation. After analysis, it is concluded that the education level of Foxconn employees is generally low, which is not conducive to the implementation of green human resources practices. Foxconn did not give full play to the leading role of supervisors in green participation practices. This study believes that enterprises should play the role of supervisors when implementing human resource green practices, and supervisors should give support and guidance when employees participate in environmental protection activities. Foxconn should focus on improving the education level of its employees. The research results of this paper are helpful for enterprises to achieve the goal of green development, help enterprises to further understand the green practice strategy of human resources, make the development of enterprises meet the requirements of green environmental protection, and improve the competitive advantage of enterprises.

The Piezocatalytic Degradation of Sulfadiazine by Lanthanum-Doped Barium Titanate.

Piezocatalysis, a heterogeneous catalytic technique, leverages the periodic electric field changes generated by piezoelectric materials under external forces to drive carriers for the advanced oxidation of organic pollutants. Antibiotics, as emerging trace organic pollutants in water sources, pose a potential threat to animals and drinking water safety. Thus, piezoelectric catalysis can be used to degrade trace organic pollutants in water. In this work, BaTiO3 and La-doped BaTiO3 were synthesized using an improved sol-gel-hydrothermal method and used as piezocatalytic materials to degrade sulfadiazine (SDZ) with ultrasound activation. High-crystallinity products with nano cubic and spherical morphologies were successfully synthesized. An initial concentration of SDZ ranging from 1 to 10 mg/L, a catalysis dosage range from 1 to 2.5 mg/mL, pH, and the background ions in the water were considered as influencing factors and tested. The reaction rate constant was 0.0378 min-1 under the optimum working conditions, and the degradation efficiency achieved was 89.06% in 60 min. La-doped BaTiO3 had a better degradation efficiency, at 14.98% on average, compared to undoped BaTiO3. Further investigations into scavengers revealed a partially piezocatalytic process for the degradation of SDZ. In summary, our work provides an idea for green environmental protection in dealing with new types of environmental pollution.